The present invention relates to an improvement in a drawbar hitch system for use on utility equipment such as farm tractors. More specifically, to a mechanism to allow for a swinging drawbar component to be conveniently moved between a swinging position and a fixed position depending upon a users needs.
Most current utility vehicles, such as tractors, have a rear hitch or drawbar system whereby a drawbar is used to connect equipment to the tractor. Commonly, this drawbar will be suppled with a half moon slide or straight slide placed at the rear of the vehicle and a series of holes and pins such that the drawbar may be pinned in a particular position or allowed to swivel or slide along the half moon. This may be useful in certain situations, such as hitching up equipment or where a certain amount of pivotal play is needed in the drawbar system for use in pulling a particular implement. The need for a pivotal drawbar may be exemplified in the use of an endless track farm vehicle such as a tractor having a left and right CATERPILLAR system. This type of vehicle is typically steered by slowing or accelerating one or the other tracks in order to move the vehicle either left or right. In this type of situation, the vehicle may make sudden and shart left or right moves depending upon a tracks acceleration or de-acceleration to move the vehicle. This can be particularly troublesome when a fixed drawbar is attached to an implement and the implement mimics these type of movements when traveling down the field. This can make it very difficult for the user to make straight rows or passes with a particular implement down the field. Thus, often times the user will adjust the drawbar mechanism so that it may pivot left or right. This is usually done by removing pins on the slide so that the drawbar can pivot as necessary.
Removal of these pins is currently done manually by getting out of the cab, going to the back when the drawbar is in a particular orientation and removing the pins. This can be very time consuming for the user of the vehicle. Further, when placing the vehicle back in transport mode for travel between fields, the user must get out, place the drawbar in a particular position and replace the pins.
From this discussion it can be seen that it would be desirable to make a system which may easily allow a user of a farm vehicle such as a tractor to switch between a drawbar that is fixed in a given position or pivotable left or right without leaving the cab. Further, it can be seen that it would be advantageous to make the system easily operated from the cab such as through a hydraulic system.
In accordance with this discussion, a moveable drawbar control system is disclosed which allows the user of a farm tractor to switch between a drawbar that is movable from side to side or fixed in a given location, without leaving the cab of the vehicle, simply through the operation of a hydraulic control.
It is the primary objective of the present invention to provide a method by which a wide variety of equipment can be attached to and pulled by a tractor which will allow for the adjustment of the position of the equipment relative to the tractor.
It is an additional objective of the present invention to provide such a method of attaching and pulling a variety of equipment with a tractor which provides a means of controlling the position of the equipment relative to the tractor either automatically or through the hydraulic control of the operator from his position inside the cab of the farm tractor.
It is a further objective of the present invention to provide such a method of controlling the orientation of equipment that is attached to and pulled by a tractor which can be accomplished within the existing configurations of such tractors and equipment in both an effective and inexpensive manner.
These objectives are accomplished by the use of a moveable drawbar control system. A typical farm tractor is equipped with a rear drawbar which is used to attach implements such as plow bottom or planters to the tractor. The drawbar is typically attached to the frame of the tractor which provides a great deal of strength to the connection which allows for the application of a large amount pulling force. Additionally, the terminal end of the drawbar is equipped with a pin hole so that any implement can be attached by use of the pin system. In a conventional attachment system, the drawbar is held in a specified position in relation to a half moon lock bar by the use of a pair of pins which are positioned within the half moon lock bar on either side of the drawbar. The removal of the lock pins then allows the drawbar to swivel back and forth along the half moon lock bar as the position of the tractor and implement change.
The present invention is designed to make this connection work with any tractor and may be especially useful on endless track type tractors. This special design is necessary because of the skid steer mechanism used to control the direction of the tractor which requires the connection to be moveable during minor directional corrections and held at the center of the lock bar during sharp turns. These operational requirements are fulfilled by the use of the present invention as it can be used to lock the drawbar in a specific location in relation to the lock bar as needed in a given situation, or to allow the drawbar to pivot freely in relation to the lock bar as may be required during use. Additionally, the activation of the present invention can be easily controlled through the tractor""s hydraulic system by the operator from inside of the tractor""s cab.
The present invention is primarily made up of a relatively long cylinder which contains a plurality of independently rotatable sleeves. These sleeves are the mounting point for the majority of the invention""s primary components, the most notable of which are the independently moveable bar lock flaps. The pivotal nature of these components is controlled through the use of an activation hydraulic cylinder which is connected to the pivot cylinder near to its center by the cylinder tab and at its rearward end to the frame of the tractor. The activation of the hydraulic cylinder either forces the tab outward in relation to the cylinder or draws it inward. The design of the invention is such that this inward and outward motion changes the orientation of the bar lock flaps between the engaged or vertical position and the disengaged or horizontal position. This is the mechanism by which the drawbar is either engaged and held in the centered position or disengaged and allowed to pivot freely along the length of the lock bar. Additionally, the bar lock flaps are biased with springs which place a rotation force on them so that they tend towards their engaged or vertical orientation when the hydraulic cylinder is engaged to move them into this position.
Therefore, if the tractor operator desires that the drawbar be allowed to pivot freely within the lock bar during operation, he simply activates the hydraulic cylinder which rotates the bar lock flaps into their disengaged or horizontal position. This moves the flaps out of the path of the drawbar and the drawbar can therefore pivot or slide freely along the lock bar. Conversely, if the operator wishes to lock the drawbar into place he retracts the hydraulic cylinder which allows the spring biased bar lock flaps to rotate back to their engaged or vertical position. The spring biased design of the bar lock flaps is important also in the fact that it allows one of the lock flaps to remain in the horizontal position if the drawbar happens to be in its way at the time of the rotational change. However, once the drawbar has cleared, the flap will then return automatically to the engaged position due to the bias of the spring. This design feature allows the present invention to be operated remotely as it ensures that the drawbar will always be locked into the desired position regardless of its position at the time of hydraulic cylinder deactivation.
For a better understanding of the present invention reference should be made to the drawings and the description in which there are illustrated and described preferred embodiments of the present invention.